348 FOOD AND FOOD ADULTERANTS. 



from wine by alcohol other organic bodies are undoubtedly taken up by 

 it (the most of which are removed in the old method, by the purification 

 with ether-alcohol) which make the results too high. The only way 

 that results could be obtained as low as the old method gave was as 

 indicated above, by long treatment in the bath with a large excess of 

 lime, and in these cases there was undoubtedly a loss of glycerine by 

 evaporation, as the following experiments show : 



1. .3645 grams pure glycerine were mixed with a small quantity of 

 lime, alcohol and water added, the whole evaporated nearly todryuess 

 on the water bath, extracted with alcohol. and the glycerine determined 

 by Legler's method in the residue from the alcoholic solution; result, 

 glycerine .303, or a loss of .0015. 



2. .3645 grams glycerine were taken and treated as above, except that 

 a large amount of lime was added ; result, .275 ; loss, .0895. 



3. .3645 grams were taken and treated as before, except that the 

 evaporation was carried to dryness, the dish being allowed to stand on 

 the bath about half an hour longer than in the other experiments ; result, 

 .251 j loss, .1135. 



Hehuer 1 has applied Legler's method to the estimation of glycerine 

 in fats, with some modifications based upon the very important fact he 

 claims to have established in his work, that '"'dilute solutions of glycer 

 ine (.6 glycerine to 1,000 of fluid) do not, as is commonly supposed, 

 volatilize in concentrating the fluid, be it on the water-bath or over the 

 naked flame." 



Other methods that have been published by Beuseman, 2 Amthor, 3 

 and Medicus, 4 are essentially slight modifications of the Berlin method, 

 and can only be referred to here. Sulmau and Berry f in their article on 

 " The Examination of Commercial Glycerine," give a very thorough 

 resume of various methods in use up to the date of the article for the 

 estimation of glycerine. 



The most recent method published is by Diez, 6 which I have not had 

 time to investigate closely. The method is quite a novel one, and differs 

 from the previously described methods in that it separates out the glyc- 

 erine as an insoluble compound, viz, as a tribenzoate of glycerine. This 

 is accomplished by shaking Hie (.5 to 1.0 per cent.) solution of glycerine 

 with benzoyl chloride after an addition of alkali. As applied to dry 

 wines it is described by the author as follows: 7 "20cc. are evapora- 

 ted to a moderately dry condition after the addition of lime. The res- 

 idue is exhausted with 20cc. of hot, 96 per cent., alcohol. After cooling 

 30cc. of water-free ether are added, and filtered after standing, the. 

 filter being washed with water- free alcohol ether (2:3). After the 

 evaporation of the solvent the glycerine is dissolved in l()-20cc. of water. 



'Analyst 12, 44. An.-ilyst 11,1-' ;iinl :'.J. 



2 Chem. Zcit. 10, 554. Zeit. f. 1'liysi... rhrm. 11. 17.' 



: K'.-p. .In-, Anal. Cli.'m., IHrili, lv!. ' /fcid.,480. 

 < Ibid, 1880, 1. 



